More recently, intrinsic scaling has been applied successfully to doubly nonlinear parabolic equations whose prototype is \(\partial _t ({\left|{u}\right|}^{p-2}u) = \mathrm {div}({\left|{\nabla u}\right|}^{p-2} u)\) , \(p>1\) , see [1]}, [2]}, [3]}.
This equation is a combination of the porous medium equation and the \(p\) -Laplace equation.
The expansion of positivity plays a fundamental role in the proofs.
